Rondo remained in Los Angeles -- reportedly for a birthday celebration -- while the Celtics traveled to Sacramento. Rondo, who continues to work his way back from a torn right ACL, was not scheduled to play against the Kings on the second night of a back-to-back, and possibly assumed he was free to miss the trip without obtaining the Celtics' permission. Rondo previously remained in Boston while the team traveled to Milwaukee for their Feb. 10 game that also was the end of a back-to-back.

Bulpett cites a source who believes Rondo remained in Los Angeles to celebrate his birthday with family members.

“His wife and kids were with him in LA, and there were some other people who came in,” a source said. “I think he felt obligated to them, too, and what they had planned for his birthday.”

Rondo didn’t want to comment on the matter before Monday night’s 110-98 loss to the Jazz. More from the Boston Herald:

That doesn’t appear to be the case. President of basketball operations Danny Ainge said yesterday he is still looking into the situation.

“I plan on talking to Rondo when he gets back into town,” he told the Herald. “I’ll find out more about what went into it, and then we’ll handle it internally. We handle all of those kind of issues internally.”